Surgical sinks are used in order to permit a surgeon to wash his hands prior to placement of the surgical gloves for later surgery. It is essential in order to maintain the sterile conditions that the surgeon not touch any object which might be unsterile. This has lead to various approaches for controlling the on and off operation of a faucet for the surgical sink which would not require the surgeon to physically touch any control knob for manipulating the faucet. Among the approaches that have been attempted is the utilization of an infrared sensor above or in the sink itself for detecting the surgeon's hands in the vicinity of the faucet such as disclosed in Rosa U.S. Pat. No. 4,942,631. A disadvantage with this approach, however, is that the faucet turns off when the surgeon's hands are moved away from the immediate vicinity of the faucet, although the washing operation has not been completed. It is then necessary to again turn on the faucet when the presence of the surgeon's hands is detected. This results an intermittent on and off action of the faucet.
Attempts to avoid the above problems have resulted in variations such as changing the beam of light in its length and scope so as to still detect the surgeon's hands when the hands are not in the immediate vicinity of the faucet. A disadvantage with this approach, however, is the detection of other objects in the beam of light causing false signals which result in the faucet being turned on even though the surgeon is not present. Other attempts have included utilizing foot operated pedals or stirrups which the surgeon would use to control actuation of the faucet. These approaches, however, are unsatisfactory in that they require actions to be taken by the surgeon when the most desirable condition would be for the surgeon to simply concentrate on a washing of the hands and not be concerned with controlling the on and off conditions of the faucet.
Another approach is illustrated in Blackmon U.S. Pat. No. 3,576,277 where hospital personnel are required to pass one hand through an electric eye mounted on the wall above the scrub sink to start and stop flow of hot and cold water. This arrangement has the disadvantage of placing the surgeon's hands in a nonsterile area around the electric eyes.